For several years, I have been reading about cyclists’ frustrations with people parking in bike lanes. Very often, the focus of these posts is the lack of attention and action offered by local enforcement agencies. Last Friday, I published my own ruminations on the topic. On the same day, a lawyer in Arlington, Virginia published a similar post, focusing specifically on the problem in the Washington, DC metro area.On Monday, I was pleasantly surprised when I spotted a tweet from the Arlington County Police Department that felt like a direct response to Friday’s calls for action: The post, which was retweeted or favorited almost two hundred times (and trolled much less than I, sadly, have come to expect), may not immediately or significantly reduce the number of drivers that park in bike lanes. However, it is certainly a positive step in beginning to increase awareness.Perhaps most importantly, it is a message that went out to the nearly six thousand people who follow the ACPD on Twitter, not just cyclists reading cycling or transportation blogs. The message was also picked up by a local news site, ARLnow.com, which helped spread the word to an even more diverse readership.In addition to explaining who is and who is not permitted to stop in a bike lane, the message from the Arlington police is to call their non-emergency line if you encounter a hazard in a bike lane. It is unclear what happens to these hazards once you report them – are officers actually dispatched to ticket illegally parked automobiles?Whether or not this campaign results in better enforcement, it is a step towards increased awareness for drivers, cyclists, and pedestrians. To have a real impact on driver behavior, however, I believe that enforcement needs to coincide with the call to report violations. We can ask motorists politely not to park in our bike lanes, and we can shame them by posting photos and videos on Twitter. But, in the end, we need real consequences, including tickets and towing, to send the message loud and clear that parking illegally in bike lanes is not acceptable.